What was it that got Kahn stranded on city alpha 5? Genetic manipulation and attempted takeover of kirk's ship, correct? If so the takeover of the enterprise by Kahn wouldn't seem to me to be big enough story for the next Star Trek. They would have to fill it out some.

I just don't see a Star Wars/Star Trek story line. Way too much hollywood political baggage connected to that idea.

Kirk retained some admiration for the determined, capable man of history. The prospect of imprisoning and rehabilitating the Augments seemed a waste. Instead, Kirk granted an opportunity for Khan and his followers: to colonize the dangerous but habitable world of Ceti Alpha V. McGivers was given the choice of facing court martial or joining the new colony. Khan accepted McGivers' company, and took up Kirk's challenge to "tame a world".